Q: I know it's now fashionable to wear shoes that match your dress or suit. If I could have my shoes covered, how much fabric should I ask for? Where would I take the shoes? How much would they charge?--A.G. A: I took your question to George Malkemus of the Manolo Blahnik shoe salon in New York. Blahnik created shoes to match the clothes previewed by many of America's most famous ready-to-wear designers during their fall openings. The list includes Bill Blass, Calvin Klein and Jeffrey Banks. Malkemus says that if the designer will sell you half a yard of the fabric, the Blahnik salon will custom-make any Blahnik shoe design of your choice in that fabric. "We do this for a lot of people," Malkemus reports. "We will custom-make shoes in any fabric as long as the material is strong enough. We did some tissue-thin chiffon shoes for Blass, but we would not recommend that fabric for anything but a show. We also covered some shoes in lace, but the lace broke. Obviously, the choice of fabric is crucial." The tapestry shoes illustrated here were made by Blahnik to match Jeffrey Banks pants. If you provide the fabric, Malkemus says, there is no additional charge beyond the price of the shoes, which sell from $240 to $325. For further information, write to Manolo Blahnik, 15 West 55th St., New York, N.Y. 10019, telephone (212) 582-3007. If you sew your own clothes, perhaps you can work out a deal with your local shoemaker.